Wait, Is It “Gross” to Keep Underwear Longer Than 6 Months?

One user on TikTok claims you should throw out your underwear every six to nine months. Here’s what ob-gyns have to say about this supposed rule.

When was the last time you threw out your old underwear? If you’re struggling to remember, first of all, same. But apparently, some people think you need to toss your skivvies roughly twice a year. See: This TikTok video claiming you should throw out your underwear every six to nine months. Um, what?!

After suffering from a recurring infection, the video’s creator said her doctor told her that, after years and years of wearing certain fabrics, it’s likely that the material won’t be “completely free and clear of bacteria” that can cause an infection — even if you’re washing said underwear after each use.

But TikTok is not known to be filled with sound advice, and restocking your underwear drawer every six months sounds expensive and, TBH, unnecessary. Here’s what ob-gyns have to say about it.

Do you really need to throw out your underwear after six to nine months?

For the record, none of the ob-gyns interviewed by Shape have even heard of this supposed underwear rule. “That’s news to me,” says Mary Jane Minkin, M.D., a clinical professor of obstetrics and gynecology and reproductive sciences at Yale Medical School.

There’s also no official guidance from the American College of Obstetricians and Gynecologists (ACOG), the ruling body of ob-gyns in the U.S., on how often you should throw out your underwear. Christine Greves, M.D., a board-certified ob-gyn at the Winnie Palmer Hospital for Women and Babies in Orlando, Florida, says she even tried searching scientific literature for something — anything — to support this claim. While a 2001 study published in the Journal of Infection suggests there might be about one-tenth of a gram of fecal matter (aka poop) on the average pair of “clean” underwear, using very hot water during your wash cycle should kill any of that lingering bacteria, says Dr. Greves.

So, from a medical standpoint, throwing out your underwear every six to nine months isn’t something you need to do, “as long as you’re washing them after each use,” says women’s health expert Jennifer Wider, M.D. And, if you do keep your underwear for longer than six months, it won’t automatically lead to a yeast infection or any other vaginal health issue, says Jessica Shepherd, M.D. an ob-gyn in Texas.

However, there’s validity to the claim that certain fabrics are less breathable and, as a result, may increase the risk of infection or other vaginal health issues, says Dr. Shepherd. “Cotton and bamboo blends are often the best, and then synthetic fabrics, such as polyester and spandex, can contribute to increased moisture, which can increase the risk of yeast infections and bacterial vaginosis,” she explains. But, again, this isn’t about how long you wear them — it’s the type of fabric, stresses Dr. Shepherd.

Some people like to toss their underwear after a yeast infection, adds Dr. Greves. But there’s no necessary medical reason for that either — again, as long as you’re washing said underwear after each use, she explains.

So, how often should you replace underwear?

Doctors say it’s really up to you. “As long as the underwear is clean, it shouldn’t cause an issue,” says Dr. Shepherd. FWIW, “clean” means the underwear has been through a hot cycle in your washing machine with soap or has at least undergone a solid hand-washing with soap and hot water to help kill yeast and bacteria that could be lurking on the fabric, explains Dr. Greves. So, even if your underwear has a visible stain, that’s okay — it doesn’t necessarily qualify it as “dirty,” as long as your underwear has been well-washed, she adds.

But if you’re struggling with regular yeast infections, it’s a good idea to switch to cotton underwear overall since it’s more breathable and better for your vagina (and, of course, touch base with your ob-gyn about how to treat or manage the infections in general), says Dr. Shepherd. Then, you can use that underwear ’til it falls apart, she says — whether that takes six months, nine months, or even several years.

Once underwear starts to fall apart or lose elasticity, it won’t necessarily hold on to more bacteria, but “it may not fit right or may not offer support,” says Dr. Wider. For that reason alone, “you can throw them away and buy a new one,” she says.